fix: don't panic if system font not found

Author: dsgallups

crates/bevy_text/src/font.rs

@@ -19,7 +19,7 @@ use bevy_reflect::TypePath;
 pub enum Font {
     /// Content of a font file as bytes
     Data(Arc<Vec<u8>>),
-    /// Reference a system font by its name
+    /// References a font installed on the system by family, weight, stretch, and style.
     System {
         /// A list of font families that satisfy this font requirement
         families: Vec<Family>,
@@ -38,7 +38,7 @@ pub enum Font {
     },
 }
 
-/// A [font family](https://www.w3.org/TR/2018/REC-css-fonts-3-20180920/#propdef-font-family).
+/// A font family specifier, either by name or generic category.
 ///
 /// See [`cosmic_text::Family`] for details.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]

crates/bevy_text/src/pipeline.rs

@@ -152,7 +152,8 @@ impl TextPipeline {
                 font_system,
                 &mut self.map_handle_to_font_id,
                 fonts,
-            );
+            )
+            .ok_or(TextError::NoSuchFont)?;
 
             // Save spans that aren't zero-sized.
             if scale_factor <= 0.0 || text_font.font_size <= 0.0 {
@@ -508,11 +509,12 @@ pub fn load_font_to_fontdb(
     font_system: &mut cosmic_text::FontSystem,
     map_handle_to_font_id: &mut HashMap<AssetId<Font>, (cosmic_text::fontdb::ID, Arc<str>)>,
     fonts: &Assets<Font>,
-) -> FontFaceInfo {
+) -> Option<FontFaceInfo> {
     let font_handle = text_font.font.clone();
-    let (face_id, family_name) = map_handle_to_font_id
-        .entry(font_handle.id())
-        .or_insert_with(|| {
+
+    let (face_id, family_name) = match map_handle_to_font_id.get_mut(&font_handle.id()) {
+        Some((face_id, family_name)) => (face_id, family_name),
+        None => {
             let font = fonts.get(font_handle.id()).expect(
                 "Tried getting a font that was not available, probably due to not being loaded yet",
             );
@@ -545,26 +547,27 @@ pub fn load_font_to_fontdb(
                         style: *style,
                     };
 
-                    //todo: unwrapping here is fallible
-                    font_system.db().query(&query).unwrap()
+                    font_system.db().query(&query)?
                 }
             };
 
             let face = font_system.db().face(face_id).unwrap();
             let family_name = Arc::from(face.families[0].0.as_str());
 
+            map_handle_to_font_id.insert(font_handle.id(), (face_id, family_name));
+            let (face_id, family_name) = map_handle_to_font_id.get_mut(&font_handle.id()).unwrap();
             (face_id, family_name)
+        }
+    };
 
-            //let other_id = font_system.db().query(query)
-        });
     let face = font_system.db().face(*face_id).unwrap();
 
-    FontFaceInfo {
+    Some(FontFaceInfo {
         stretch: face.stretch,
         style: face.style,
         weight: face.weight,
         family_name: family_name.clone(),
-    }
+    })
 }
 
 /// Translates [`TextFont`] to [`Attrs`].